File: /var/dev/nowruzgan/admin/node_modules/@mapbox/point-geometry/README.md
# point-geometry
[](http://travis-ci.org/mapbox/point-geometry) [](https://coveralls.io/r/mapbox/point-geometry?branch=master)
a point geometry with transforms
### `Point(x, y)`
A standalone point geometry with useful accessor, comparison, and
modification methods.
### Parameters
| parameter | type | description |
| --------- | ------ | -------------------------------------------------------------------------------------- |
| `x` | Number | the x-coordinate. this could be longitude or screen pixels, or any other sort of unit. |
| `y` | Number | the y-coordinate. this could be latitude or screen pixels, or any other sort of unit. |
### Example
```js
var point = new Point(-77, 38);
```
### `clone`
Clone this point, returning a new point that can be modified
without affecting the old one.
**Returns** `Point`, the clone
### `add(p)`
Add this point's x & y coordinates to another point,
yielding a new point.
### Parameters
| parameter | type | description |
| --------- | ----- | --------------- |
| `p` | Point | the other point |
**Returns** `Point`, output point
### `sub(p)`
Subtract this point's x & y coordinates to from point,
yielding a new point.
### Parameters
| parameter | type | description |
| --------- | ----- | --------------- |
| `p` | Point | the other point |
**Returns** `Point`, output point
### `multByPoint(p)`
Multiply this point's x & y coordinates by point,
yielding a new point.
### Parameters
| parameter | type | description |
| --------- | ----- | --------------- |
| `p` | Point | the other point |
**Returns** `Point`, output point
### `divByPoint(p)`
Divide this point's x & y coordinates by point,
yielding a new point.
### Parameters
| parameter | type | description |
| --------- | ----- | --------------- |
| `p` | Point | the other point |
**Returns** `Point`, output point
### `mult(k)`
Multiply this point's x & y coordinates by a factor,
yielding a new point.
### Parameters
| parameter | type | description |
| --------- | ----- | ----------- |
| `k` | Point | factor |
**Returns** `Point`, output point
### `div(k)`
Divide this point's x & y coordinates by a factor,
yielding a new point.
### Parameters
| parameter | type | description |
| --------- | ----- | ----------- |
| `k` | Point | factor |
**Returns** `Point`, output point
### `rotate(a)`
Rotate this point around the 0, 0 origin by an angle a,
given in radians
### Parameters
| parameter | type | description |
| --------- | ------ | ---------------------------------- |
| `a` | Number | angle to rotate around, in radians |
**Returns** `Point`, output point
### `rotateAround(a, p)`
Rotate this point around p point by an angle a,
given in radians
### Parameters
| parameter | type | description |
| --------- | ------ | ---------------------------------- |
| `a` | Number | angle to rotate around, in radians |
| `p` | Point | Point to rotate around |
**Returns** `Point`, output point
### `matMult(m)`
Multiply this point by a 4x1 transformation matrix
### Parameters
| parameter | type | description |
| --------- | ----------------- | --------------------- |
| `m` | Array\.\<Number\> | transformation matrix |
**Returns** `Point`, output point
### `unit`
Calculate this point but as a unit vector from 0, 0, meaning
that the distance from the resulting point to the 0, 0
coordinate will be equal to 1 and the angle from the resulting
point to the 0, 0 coordinate will be the same as before.
**Returns** `Point`, unit vector point
### `perp`
Compute a perpendicular point, where the new y coordinate
is the old x coordinate and the new x coordinate is the old y
coordinate multiplied by -1
**Returns** `Point`, perpendicular point
### `round`
Return a version of this point with the x & y coordinates
rounded to integers.
**Returns** `Point`, rounded point
### `mag`
Return the magitude of this point: this is the Euclidean
distance from the 0, 0 coordinate to this point's x and y
coordinates.
**Returns** `Number`, magnitude
### `equals(other)`
Judge whether this point is equal to another point, returning
true or false.
### Parameters
| parameter | type | description |
| --------- | ----- | --------------- |
| `other` | Point | the other point |
**Returns** `boolean`, whether the points are equal
### `dist(p)`
Calculate the distance from this point to another point
### Parameters
| parameter | type | description |
| --------- | ----- | --------------- |
| `p` | Point | the other point |
**Returns** `Number`, distance
### `distSqr(p)`
Calculate the distance from this point to another point,
without the square root step. Useful if you're comparing
relative distances.
### Parameters
| parameter | type | description |
| --------- | ----- | --------------- |
| `p` | Point | the other point |
**Returns** `Number`, distance
### `angle`
Get the angle from the 0, 0 coordinate to this point, in radians
coordinates.
**Returns** `Number`, angle
### `angleTo(b)`
Get the angle from this point to another point, in radians
### Parameters
| parameter | type | description |
| --------- | ----- | --------------- |
| `b` | Point | the other point |
**Returns** `Number`, angle
### `angleWith(b)`
Get the angle between this point and another point, in radians
### Parameters
| parameter | type | description |
| --------- | ----- | --------------- |
| `b` | Point | the other point |
**Returns** `Number`, angle
### `angleWithSep(x, y)`
Find the angle of the two vectors, solving the formula for
the cross product a x b = |a||b|sin(θ) for θ.
### Parameters
| parameter | type | description |
| --------- | ------ | ---------------- |
| `x` | Number | the x-coordinate |
| `y` | Number | the y-coordinate |
**Returns** `Number`, the angle in radians
### `convert(a)`
Construct a point from an array if necessary, otherwise if the input
is already a Point, or an unknown type, return it unchanged
### Parameters
| parameter | type | description |
| --------- | ------------------------ | ----------------------- |
| `a` | Array\.\<Number\>\,Point | any kind of input value |
### Example
```js
// this
var point = Point.convert([0, 1]);
// is equivalent to
var point = new Point(0, 1);
```
**Returns** `Point`, constructed point, or passed-through value.
## Installation
Requires [nodejs](http://nodejs.org/).
```sh
$ npm install point-geometry
```
## Tests
```sh
$ npm test
```